Endoscopic instrument and method for manufacturing thereof

ABSTRACT

An endoscopic instrument according to the present invention includes: a wire disposed in a flexible sheath and capable of freely projecting relative to the flexible sheath, the distal end of the wire expanding in radius to form a loop section or a basket section upon being projected from the sheath; and a fixture cylinder for fixing the inserted proximal end of the wire, wherein the fixture cylinder is provided with a wire-radius-increasing-direction-regulating section for regulating the direction in which the radius of the wire increases; and a wire-fixing section, disposed in the vicinity of the proximal end relative to the wire-radius-increasing-direction-regulating section, for fixing the wire.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. Ser. No.11/924,271, filed Oct. 25, 2007, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscopic instrument and a methodfor manufacturing thereof.

2. Background Art

A snare for use in endoscopic polypectomy conducted in a body cavity isa wire bent in a U-shape to form a loop having a proximal end connectedto a maneuvering wire capable of extending and retracting in a sheath.Maneuvering, e.g. retracting the maneuvering wire, causes the loopsection to be retracted into a distal end of the sheath, therebyreducing the radius of the loop which is constricting a polyp ordischarging a high-frequency electric current if necessary.

The proximal end of a snare wire of such kind is inserted into a metalfixture cylinder as disclosed by Japanese Unexamined Patent Application,First Publication No. H9-210367 and fixed to the fixture cylinder in oneunit by filling a brazing filler metal or solder into the fixturecylinder or by crimping the fixture cylinder. To be more specific, afixture specially designed for maintaining a position, e.g., a directionof the loop plane projecting from the sheath is used for fixing theproximal end of the snare wire to the fixture cylinder.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an endoscopicinstrument and a method for manufacturing the endoscopic instrument thatcan fix the proximal end of a wire to a fixture cylinder and regulate awire-radius-increasing-direction upon projecting the distal end of awire from the sheath.

An endoscopic instrument according to an aspect of the present inventionincludes: a wire disposed in a flexible sheath and capable of freelyprojecting relative to the flexible sheath, the distal end of the wireexpanding in radius to form a loop section or a basket section uponbeing projected from the sheath; and a fixture cylinder for fixing theinserted proximal end of the wire, wherein the fixture cylinder isprovided with a wire-radius-increasing-direction-regulating section forregulating the direction in which the radius of the wire increases; anda wire-fixing section, disposed in the vicinity of the proximal endrelative to the wire-radius-increasing-direction-regulating section, forfixing the wire.

A method according to an aspect of the present invention formanufacturing an endoscopic instrument including a wire disposed in aflexible sheath and capable of freely projecting relative to theflexible sheath, the distal end of the wire expanding in radius to forma loop section or a basket section upon being projected from the sheathincludes: a step for inserting a proximal end of the wire into a metalfixture cylinder; a first-crimping step for crimping the fixturecylinder to form a wire-radius-increasing-direction-regulating sectionwhich regulates the direction in which the radius of the wire increasesupon forming a loop section or a basket section; and a second-crimpingstep for forming a wire-fixing section for fixing the wire by crimpingthe vicinity of the proximal end relative to thewire-radius-increasing-direction-regulating section of the fixturecylinder.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an endoscopic instrument inserted into achannel of an endoscope according to an embodiment of the presentinvention.

FIG. 2 is a cross-section showing the structure of a distal end of theendoscopic instrument.

FIG. 3 is a cross-sectional view taken along a line III-III in FIG. 2.

FIG. 4 is a cross-sectional view taken along a line IV-IV in FIG. 2.

FIG. 5 is a perspective view showing how to manufacture the endoscopicinstrument according to the embodiment.

FIG. 6 is a cross sectional view showing how to manufacture theendoscopic instrument according to the embodiment.

FIG. 7 is a general view of the endoscopic instrument according to theembodiment.

FIG. 8 is a perspective view partly showing the structure of amaneuvering section of the endoscopic instrument according to theembodiment.

FIG. 9 is a perspective view showing the structure of a maneuveringsection of the endoscopic instrument according to the embodiment.

FIG. 10 is a flowchart showing how to fix a high-frequency incision wireto a fixture cylinder in the endoscopic instrument according to theembodiment.

FIG. 11 is a cross-section showing another example of a distal end ofthe endoscopic instrument according to the embodiment.

FIG. 12 is a perspective view showing another example of how tomanufacture the distal end of the endoscopic instrument according to theembodiment.

FIG. 13 is a perspective view showing another example of how tomanufacture the distal end of the endoscopic instrument according to theembodiment.

FIG. 14 is a flowchart showing how to manufacture another example of thedistal end of the endoscopic instrument according to the embodiment.

FIG. 15 is a flowchart showing another example of how to manufacture thedistal end of the endoscopic instrument according to the embodiment.

PREFERRED EMBODIMENTS

Embodiments will be hereafter explained in detail.

Structural elements that are equivalent in the following explanationwill be assigned the same numeric symbols and redundant explanationsthereof will be omitted.

FIG. 1 is a perspective view of an endoscopic instrument inserted into achannel of an endoscope. In the drawing, reference numeral 1 indicatesan endoscope. The endoscope 1 has an insertion section 1 a having achannel 2 that allows part of an endoscopic instrument 10 to extend orretract therethrough.

The endoscopic instrument 10 includes a flexible sheath 11 insertedthrough the channel 2 of the endoscope; a high-frequency incision wire12 capable of freely projecting or retracting relative to the sheath 11;and a maneuvering section 14 for increasing or reducing the radius ofthe high-frequency incision wire 12 via a maneuvering wire 13.

The sheath 11 is made of resin electrically insulative and harmless tohumans, e.g., polytetrafluoroethylene. In addition, the outer radius ofthe sheath 11 is set to allow insertion thereof into the channel 2 ofthe endoscope 1; and the inner radius is set to allow insertion of thehigh-frequency incision wire 12 therethrough.

FIG. 2 is a cross-sectional view showing the structure where thehigh-frequency incision wire is fixed to the fixture cylinder; FIG. 3 isa cross-sectional view taken along the line III-III in FIG. 2; and FIG.4 is a cross-sectional view taken along the line IV-IV in FIG. 2.

As illustrated in the drawings, the distal end of the high-frequencyincision wire 12 having a precurve pushed out of the sheath 11 expandsto form a loop section 12 a. In addition, a folding section 12 b isformed on the center of the distal end of the high-frequency incisionwire 12. Furthermore, the proximal end of the high-frequency incisionwire 12 has two end sections 12 c and 12 c inserted and fixed in thewire-fixing section 15.

In the present specification, it should be noted that a “distal end”indicates an end having the high-frequency incision wire 12 attached tothe endoscopic instrument 10; and a “proximal end” indicates an endhaving the maneuvering section 14 attached to the endoscope instrument10.

The wire-fixing section 15 is provided with awire-radius-increasing-direction-regulating section 16, disposed to thedistal end, for regulating the direction in which the radius of thehigh-frequency incision wire 12 increases; and a wire-fixing section 17,disposed in substantially the middle of longitudinal direction, forfixing the two end sections 12 c and 12 c of the high-frequency incisionwire 12. The wire-fixing section 15 is made from metal material, e.g.,stainless steel. As illustrated in FIG. 5, extruding punches 18 a and 18a in two opposed directions to crimp the two end sections 12 c and 12 cinserted through a hole 15 a at the proximal end of the high-frequencyincision wire 12 allows the wire-radius-increasing-direction-regulatingsection 16 to be formed. In addition, extruding punches 18 b in fourdirections each shifted by 90 degrees and crimping the wire-fixingsection 15 form a wire-fixing section 17. FIG. 5 is a perspective viewshowing how to crimp the wire-fixing section 15 by the punches 18 a and18 b. The fixed state of two end sections 12 c and 12 c of thehigh-frequency incision wire 12 as illustrated in FIG. 5 reach thewire-fixing section 17 of the wire-fixing section 15.

The wire-radius-increasing-direction-regulating section 16 formed by thepunches 18 a crimping in two opposed directions has, in total, tworecessing sections 16 a shifted by 180 degrees on the outer peripherythereof. Also, the wire-fixing section 17 formed by the punches 18 bcrimping in four directions each shifted by 90 degrees has, in total,four recessing sections 17 a on the outer periphery thereof. It shouldbe noted that the punches 18 b undertaking crimping of the wire-fixingsection 17 are not limited to four pieces as long as they are plural.

The wire-radius-increasing-direction-regulating section 16 is providedwith wire passageways 16 b and 16 b each of which introduces one of thetwo end sections 12 c and 12 c of the high-frequency incision wire 12.The previous crimping of the inner periphery wall of the wire-fixingsection 15 to project inwardly and the previous crimping of the innercurved surface of the wire-fixing section 15 to impart a greatercurvature form the wire passageway 16 b. Also, thewire-radius-increasing-direction-regulating section 16 is formed so thatthe high-frequency incision wire 12 will not move in the directionorthogonal to the axial direction of the wire-fixing section 15. Inaddition, the wire-radius-increasing-direction-regulating section 16regulates the direction in which the radius of the high-frequencyincision wire 12 increases, while thewire-radius-increasing-direction-regulating section 16 permits rotationof the high-frequency incision wire 12 around the axial line relative tothe wire-fixing section 15, and movement of the high-frequency incisionwire 12 in the axial direction relative to the wire-fixing section 15.

As illustrated in FIGS. 2 and 3, the direction in which a plurality ofwire passageways 16 b are disposed coincides with the direction in whichthe high-frequency incision wire 12 expands.

FIG. 7 is a general view of an endoscopic instrument 10 including themaneuvering section 14. As illustrated in the drawing, the maneuveringsection 14 is provided with a rotative operation section 20 and asliding-operation section 21 that are assembled in one unit. Therotative operation section 20 rotates the high-frequency incision wire12 around the axial line of the sheath 11 via the maneuvering wire 13.The sliding-operation section 21 provided to the proximal end of therotative operation section 20 slides the high-frequency incision wire 12in the axial line direction of the sheath 11 via the maneuvering wire13.

FIG. 8 is a perspective view showing the detail of the rotativeoperation section 20 and the sliding-operation section 21. Asillustrated in FIG. 8, the rotative operation section 20 is providedwith a rotating-member-supporting casing 22 and a rotating member 23.The rotating-member-supporting casing 22 is fixed to the proximal end ofthe sheath 11. The rotating member 23, disposed in therotating-member-supporting casing 22, can rotate around the axial lineof the sheath 11 relative to the rotating-member-supporting casing 22while movement of the rotating member 23 in the axial line direction ofthe sheath 11 is regulated.

Formed in substantially the center of the rotating member 23 is apolygonal, e.g., hexagonal through hole 23 a, through which a rod 24having the corresponding hexagonal cross-section is inserted. Thisallows the rotating member 23 to rotate around the axial line of thesheath 11 relative to the rod 24 and to move the rotating member 23 inthe axial line direction relative to the rod 24. The rod 24 is coaxiallyconnected to the proximal end section of the maneuvering wire 13.

The sliding-operation section 21 is provided with a maneuvering sectionmain unit 25 and a slider 26, capable of moving the axial line directionof the rod 24, attached to the maneuvering section main unit 25. Themaneuvering section main unit 25, fixed to the proximal end of therotating-member-supporting casing 22 can move the rod 24 capable ofrotating around its axial line direction and enclose the rod 24 therein.

A connecting rod 28 is attached to the proximal end of the rod 24coaxially. A fitting section 29 has two separated branch sections 29 aat the proximal ends of the connecting rod 28 (See FIG. 9). The fittingsection 29 is inserted into a fitting hole 31 a formed on the inner endbase section 31 of the plug 30. The fitting section 29 in this fittingstate can rotate around the axial line of the connecting rod 28 relativeto the fitting hole 31 a of the plug 30 while the movement of thefitting section 29 relative to the connecting rod 28 in the axial linedirection is regulated. In addition, the distal end of the plug 30assembled to the slider 26 is exposed outwardly.

It should be noted that the maneuvering wire 13, the rod 24, theconnecting rod 28, and the plug 30 made from conductive material, e.g.,metal, can transfer high-frequency electric current introduced from theplug 30 to the high-frequency incision wire 12.

In addition, a finger hook ring 25 a is provided to the maneuveringsection main unit 25, and a finger hook ring 26 a is provided to theslider 26.

Explained next with reference to FIG. 10 will be a method for fixing thehigh-frequency incision wire 12 to the wire-fixing section 15 in theendoscopic instrument of the present invention.

To start with, the high-frequency incision wire 12 is cut into apredetermined length; and precurve having a predetermined direction isimparted thereto.

The two end sections 12 c, 12 c provided to the proximal end of thehigh-frequency incision wire 12 having precurve are inserted from aboveand into a hole 15 a of the wire-fixing section 15 (insertion step; stepS1).

As illustrated in FIG. 5, subsequently projecting punches 18 a and 18 ain opposed two opposing directions toward the distal end of thewire-fixing section 15 forms thewire-radius-increasing-direction-regulating section 16 (first-crimpingstep; step S2).

Subsequently projecting four punches 18 b each disposed every 90 degreestoward in a middle section in the longitudinal direction of thewire-fixing section 15 in a second-crimping step forms the wire-fixingsection 17 (second-crimping step; step S3).

The aforementioned steps allow the high-frequency incision wire 12 to befixed to the wire-fixing section 15.

Explained next will be a method for incising a lesion site of a patientwith an endoscopic instrument 10 having the aforementionedconfiguration.

To start with, the sheath 11 enclosing the loop section 12 a of thehigh-frequency incision wire 12 and inserted into the channel 2 of theinsertion section 1 a of the endoscope 1 is inserted into the bodycavity of a patient. Partially injecting a normal saline solution ifnecessary elevates the lesion site found by observation using this stateof the endoscope 1.

Subsequently, the slider 26 of the maneuvering section 14 is maneuveredto extend toward the distal end. The maneuvering of the slider 26transferred to the high-frequency incision wire 12 via the plug 30, theconnecting rod 28, the rod 24, and the maneuvering wire 13 cause thehigh-frequency incision wire 12 to project relative to the distal end ofthe sheath 11 as illustrated in FIG. 1. The high-frequency incision wire12 upon projecting restores, i.e., expands, the loop section 12 a.

The loop section 12 a of this state of the high-frequency incision wire12 is hooked on the lesion site. Rotating the rotating member 23 of themaneuvering section 14 provides an appropriate angle of rotation to thisstate of the loop section 12 a which is not in parallel with the lesionsite, i.e., inclined relative to the lesion site. That is, rotationtorque of the rotating member 23 is transferred to the high-frequencyincision wire 12 via a hexagonal rod 24 and the maneuvering wire 13,thereby allowing the loop section 12 a of the high-frequency incisionwire 12 to rotate around the axial line of the sheath 11. Although thisstate of the connecting rod 28 connected to the rod 24 rotates with therod 24 rotating around the axial line of the rotating member 23, theplug 30 and the slider 26 will not rotate around the axial line of therod 24 since the connecting rod 28 capable of rotating relative to theplug 30 is attached to the plug 30.

Therefore, rotating the rotating member 23 can vary the direction of theloop section 12 a of the high-frequency incision wire 12 at an arbitraryangle, thereby facilitating the hooking of the loop section 12 a ontothe lesion site.

Subsequently, the slider 26 is retracted toward the proximal end and thehigh-frequency incision wire 12 is retracted into the sheath 11 whilethe distal end of the sheath 11 is pressed to the vicinity of the lesionsite. The elevated lesion site is constricted with this state of thehigh-frequency incision wire 12. Supplying high frequency electriccurrent to this state of the plug 30 can incise the lesion site andnormal tissue therearound constricted by the high-frequency incisionwire 12.

The wire-fixing section 15 of the endoscopic instrument having theaforementioned configuration, i.e., provided with thewire-radius-increasing-direction-regulating section 16 for regulatingthe direction in which the radius of the high-frequency incision wire 12increases; and the wire-fixing section 17, provided in the vicinity ofthe proximal end relative to thewire-radius-increasing-direction-regulating section 16, for fixing thehigh-frequency incision wire 12 can direct and fix a plane defined bythe loop section 12 a at an arbitrary direction without using a specificfixture that positions the loop section of the wire, therebyfacilitating the fixing of the high-frequency incision wire 12 using thewire-fixing section 15 by carrying out the aforementioned first-crimpingstep S2 and a second-crimping step S3.

In addition, the structure of thewire-radius-increasing-direction-regulating section 16 regulating thedirection in which the radius of the high-frequency incision wire 12increases and permitting rotation of the wire around the axial linerelative to the wire-fixing section 15 and movement of the wire relativeto the wire-fixing section 15 in the axial direction merely regulatesthe direction in which the radius increases, but thewire-radius-increasing-direction-regulating section 16 does not fix thehigh-frequency incision wire 12, thereby preventing unnecessary loadfrom being applied to the two end sections 12 c, 12 c of thehigh-frequency incision wire between thewire-radius-increasing-direction-regulating section 16 and thewire-fixing section 17.

In addition, the wire passageways 16 b, 16 b, for guiding each one ofthe two end sections 12 c, 12 c of the high-frequency incision wires,provided to the wire-radius-increasing-direction-regulating section 16can regulate the direction of the high-frequency incision wire, i.e., aplane defined by the expanding loop section 12 a.

In addition, the wire passageway 16 b formed partially by compressingthe inner periphery wall of the wire-fixing section 15 inwardly issusceptible to simpler structure and cost reduction relative to a casein which a separate member is attached to the wire-fixing section 15 toform a wire passageway.

In addition, intervention for polyp, etc. are facilitated; thus,operability improves since the rotative operation section 20 forrotating the high-frequency incision wire 12 and the sliding-operationsection 21 for moving the high-frequency incision wire 12 in the axialline direction are assembled to the maneuvering section 14 in one unit.Also reducing the component count and average number of man-hoursnecessary for assembly can achieve cost reduction.

Modified Examples

FIG. 11 shows a modified example of the high-frequency incision wire 30.

This modified example is different from the aforementioned configurationin that the direction of the plane defined by the loop section 30 a ofthe high-frequency incision wire 30 relative to the wire-fixing section15 is different.

That is, the direction in which the wire passageways 16 b, 16 b aredisposed coincides with the direction in which the radius of thehigh-frequency incision wire 12 increases as illustrated in FIG. 2. Incontrast, a direction X1 in which wire passageways 30 b, 30 b aredisposed is shifted by 90 degrees relative to a radius-increasingdirection X2 of the high-frequency incision wire 12, i.e., the planedefined by the loop section 30 a.

Therefore, shifting the direction X1 in which the wire passageways 30 b,30 b are disposed relative to the radius-increasing direction X2 of thehigh-frequency incision wire 12 provides a smooth deformation of thehigh-frequency incision wire 12 with its restoring force projecting fromthe sheath 11 wire, thereby resulting in gradual expansion andrestoration of the loop section 30 a.

FIGS. 12 and 13 are perspective views for explaining how to manufacturethe modified example of the endoscopic instrument. FIG. 14 is aflowchart therefor.

The method shown in FIG. 14 for manufacturing the modified example isthe same as the manufacturing method that was previously explained withreference to FIG. 10 in that the method of FIG. 14 includes: a step forinserting two ends of the high-frequency incision wire 12 into holes ofthe wire-fixing section 15 (step S11, see FIG. 12); a first-crimpingstep for projecting punches in two opposed directions toward the distalend of the wire-fixing section 15 to form thewire-radius-increasing-direction-regulating section 36 (step S12); and asecond-crimping step for projecting four punches 18 b each shifted byevery 90 degrees toward the middle section of the wire-fixing section 15in longitudinal direction to form the wire-fixing section 17 (step S14,see FIG. 13).

The modified example further includes a twisting step (step S13) fortwisting the distal end of the high-frequency incision wire 12 aroundthe axial line of the wire-fixing section 15 between the first-crimpingstep and the second-crimping step.

Therefore, merely adding the twisting step (step S13) between thefirst-crimping step (step S12) and the second-crimping step (step S14)provides the structure for fixing the high-frequency incision wire 12 tothe wire-fixing section 15 as illustrated in FIG. 11 without using aspecific fixture.

Here, the technical range of the present invention is not limited to theabove embodiment; thus, various modification can be added withoutdeviating from the effects and structures of the present invention.

The method for manufacturing the modified example as illustrated in FIG.14 is not limited to a configuration in which the twisting step S13 isincluded between the first-crimping step S12 and the second-crimpingstep S14. The endoscopic instrument as illustrated in the modifiedexample may be manufactured by a method including an insertion step S21;a twisting step S22; a first-crimping step S12; and a second-crimpingstep S24 in order as shown in FIG. 15.

To be more specific, two end sections of a high-frequency incision wire12 are inserted into two separated guide members which are not shown inthe drawing. Subsequently, the two end sections of the high-frequencyincision wire 12 are inserted into holes of a wire-fixing section 15while the end sections of the wires are inserted into the guide members.That is, the insertion step S21 has two steps. Subsequently, the distalend of the wire is twisted around its axial line while the movement ofthe distal end of the wire in any direction other than the axial line isregulated by the two-separated guide members. This is conducted by thetwisting step S22. Subsequent to this step, the method further includesa first-crimping step S23 and a second-crimping step S24. Thehigh-frequency incision wire 12 according to the modified example can bemanufactured by this manufacturing method.

The aforementioned embodiment is not limited to a configuration in whichthe high-frequency incision wire 12 is crimped to be fixed to thewire-fixing section 15. That is, the high-frequency incision wire 12 maybe fixed to the wire-fixing section 15 by a brazing method or by thecombination of a brazing method and a crimping method.

In addition, the aforementioned embodiment is not limited to aconfiguration in which the wire-radius-increasing-direction-regulatingsection 16 is provided to the distal end of the wire-fixing section 15and the wire-fixing section 17 is provided in the middle of thewire-fixing section 15 in longitudinal length. That is, awire-radius-increasing-direction-regulating section 16 may be providedin the middle of the wire-fixing section 15 in longitudinal length; anda wire-fixing section may be provided to the proximal end of thewire-fixing section 15.

Also, the present invention is not limited to a configuration in which apart of the wire passageway 16 b is formed by projecting the innerperiphery wall of the wire-fixing section 15. The wire passageway 16 bis formed partially by a separate member other than a component formingthe wire-fixing section 15.

1. A method for manufacturing an endoscopic instrument including a wiredisposed in a flexible sheath and capable of freely projecting relativeto the flexible sheath, the distal end of the wire expanding in radiusto form a loop section or a basket section upon being projected from thesheath, the method comprising: a step for inserting a proximal end ofthe wire into a metal fixture cylinder; a first-crimping step forcrimping the fixture cylinder to form awire-radius-increasing-direction-regulating section which regulates thedirection in which the radius of the wire increases upon forming a loopsection or a basket section; and a second-crimping step for forming awire-fixing section for fixing the wire by crimping the vicinity of theproximal end relative to the wire-radius-increasing-direction-regulatingsection of the fixture cylinder.
 2. The method according to claim 1 formanufacturing the endoscopic instrument, further comprising a twistingstep for twisting the distal end of the wire around an axial linerelative to the fixture cylinder, the twisting step being conducted atleast between the inserting step and the first-crimping step or betweenthe first-crimping step and the second-crimping step.